Carr Lock® Secondary Liner Bushings

Carr Lock System

Product Information

The Carr Lock® System requires that each fixture plate have one mounting hole designated as the primary reference hole (Primary Liner Bushing) and one mounting hole designated as the secondary reference hole (Secondary Liner Bushing or Slotted Locator Bushing). All other mounting holes should be drilled clearance holes used for clamping only, not locating, .015-.030" over nominal size. Secondary Liner Bushings have slight ID clearance (+.0010/+.0020" tolerance) to avoid binding. Made in USA.

Secondary Liner Bushings are available for all Carr Lock® Clamp shank diameters, each in a choice of lengths for different top plate thicknesses (both inch and metric):

13mm

16mm

20mm

25mm

30mm

35mm

50mm

Application Information

Each mounting point consists of three components:

(1) Carr Lock® Clamp, with a precisely ground shank

(2) Carr Lock® Liner Bushing or clearance hole in the top plate

(3) Carr Lock® Receiver Bushing in the subplate

Each top plate should have one Carr Lock Mount designated as its primary reference point, and one as its secondary reference point. These two mounts should be as far apart as possible. The secondary reference point should have a relieved liner to avoid redundant location (binding). Additional Carr Lock Mounts can be used for more clamping force, but these should be installed in clearance holes, not locating liners. Note that the same Carr Lock Clamp fits any type of liner or a clearance hole.

Primary Reference Hole

Each fixture plate must have one Primary Liner Bushing as its primary reference point. Primary Liners have a tight ID (+.0002/+.0007" tolerance) to provide precise reference in two-axes.

Secondary Reference Hole

Each fixture must have one secondary reference point, either a Secondary Liner Bushing or a Slotted Locator Bushing. Secondary Liners have an extra .001" ID clearance (+.0012/+.0017" tolerance) to avoid binding. Slotted Locator Bushings have a tight ID tolerance in one direction and full relief in the perpendicular direction. Slotted Locator Bushings provide better accuracy than Secondary Liners, but take a few extra steps to install, and are not available in all sizes. Note: a Primary Liner could theoretically be used as a secondary reference if hole locations are held to +/-.0002".

Material

MATERIAL	HEAT TREAT	FINISH	DFARS	RoHS
1144 Steel	heat treated Rc 58-64	Black Oxide	✔	✔

Click here for detailed material and finish specifications.

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